The flavoring chemicals in e cigarettes are linked to a disease known as popcorn lung Teens making dangerous changes to vaping devices E Cigarette Poisoning Children's Safety Network Vaping has become common, but it's important to know what you're inhaling. Many e cigarettes contain nicotine, heavy metals like nickel and lead, and chemicals that can harm your lungs and overall health. The Facts on Vaping E Cigarettes: Safer But Not Safe